#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
typedef long long LL;
using namespace std;
LL q[107], c[37], cnt[37], myput[107];
int main() {
    cin.sync_with_stdio(false);
    LL n,qn,s;
    cin>>n>>qn>>s;
    LL cun, qu;
    LL Cn=0;
    for (int i=1; i<=s; ++i) cin>>q[i];
    for (int i=1; i<=qn; ++i) cin>>c[i], Cn+=c[i];
    LL all=0;
    bool flag=true;
    for (int i=1; i<=n; ++i) {
        cin>>qu;
        memset(cnt, 0, sizeof(cnt));
        cun=0;
        for (int i=1; i<=s; ++i) {
            cin>>myput[i];
            cun+=myput[i];
            cnt[q[i]]+=myput[i];
        }
        for (int i=1; i<=qn; ++i) {
            if (cnt[i]>c[i]) flag=false;
        }
        if (cun+all>Cn) flag=false;
        if (!flag) break;
        all+=cun;
        all-=qu;
        if (all<0) all=0;
    }
    if (all>0) flag=false;
    if (flag) printf("possible\n");
    else printf("impossible\n");
    return 0;
}
